Over on the Fire and Light page, I recommend wood fires. A recent visitor to this site asked if wood burning is not bad for the environment, and I went to do some research on it. The answer is essentially that wood burning is not environmentally unfriendly, although there are some aspects of it you should consider.
Burning wood releases the carbon that is “stored” or “sequestered” in the timber. This contributes to the presence of CO2 in the atmosphere, which was originally “drawn down” by the growing tree. However, this carbon would have been released in the near future in any case, as the tree dies, rots, and decays in the normal manner, and it’s drawn down again by new trees growing where the old one was.
Because of that, it’s important to make sure that your wood for burning is coming from businesses that support sustainable forestry, which plant trees to replace the ones that are cut. Generally, this is a sensible use of land in the first place, so it’s not hard to find. Firewood is also often a side product of wood cut for lumber, and it makes sense to make use of it for fuel.
Something to watch out for is the amount of smoke. While wood does not give off as much smoke as coal, it can contribute in a small way to urban smog. On foggy or still days, wood smoke may hang in the air. Otherwise, it produces far less smoke, and less acidic smoke, than coal or other “smoky” fuels.
So: wood burning is environmentally sound, as long as it’s from sustainable forestry.